Real-world Outcomes of Ipilimumab Plus Nivolumab Combination Therapy in a Nation-wide Cohort of Advanced Melanoma Patients in the Netherlands

In phase III trials, ipilimumab plus nivolumab combination therapy is highly efficacious for advanced melanoma, despite many treatment-related grades 3-4 adverse events. Here, we report real-world safety and survival outcomes of ipilimumab plus nivolumab for advanced melanoma. Patients with advanced melanoma who received first-line ipilimumab plus nivolumab between January 1, 2015 and June 30, 2021 were selected from the Dutch Melanoma Treatment Registry. We evaluated response status at 3, 6, 12, 18, and 24 months. OS and PFS were estimated with the Kaplan-Meier method. Separate analyses were performed for patients with or without brain metastases and for patients who met the inclusion criteria of the Checkmate-067 trial. In total, 709 patients received first-line ipilimumab plus nivolumab. Three hundred sixty (50.7%) patients experienced grade 3-4 adverse events, with 211 of the (58.6%) patients requiring hospital admission. The median treatment duration was 42 days (IQR = 31-139). At 24 months, disease control was achieved in 37% of patients. Median PFS since the start of treatment was 6.6 months (95% CI: 5.3-8.7), and median OS was 28.7 months (95% CI: 20.7-42.2). CheckMate-067 trial-like patients had a 4-year OS of 50% (95% CI: 43-59). Among patients with no asymptomatic or symptomatic brain metastases, the 4-year OS probabilities were 48% (95% CI: 41-55), 45% (95% CI: 35-57), and 32% (95% CI: 23-46). Ipilimumab plus nivolumab can achieve long-term survival in advanced melanoma patients in a real-world setting, including patients not represented in the CheckMate-067 trial. However, the proportion of patients with disease control in the real world is lower compared with clinical trials.